Fastening arrangement for open hose clamp

ABSTRACT

A clamp structure with a clamping band having open ends and a mechanical interconnection of the open ends of the band that include at least two outwardly extending hooks in the inner band portion adapted to engage in apertures in the outer band portion; at least one of the hooks is a cold-deformed support hook and another one of the hooks is a generally circumferentially extending combined guide and support hook which has an inclined guide and support surface operable to initially engage with the corresponding aperture in the outer band portion so as to guide the inner and outer band portions toward one another while at the same time absorbing circumferentially directed tightening forces until the cold-deformed support hook becomes effective in also absorbing tightening forces by engagement of its abutment surface with the corresponding aperture.

This application is a continuation-in-part application of my priorapplication Ser. No. 446,503 entitled "Earless Clamp Structure" andfiled in the U.S. Patent and Trademark Office on Dec. 3, 1982.

The present invention relates to a fastening arrangement for open clampstructures.

BACKGROUND OF THE INVENTION

As pointed out in the aforementioned copending application, so-calledopen clamp structures are known in the prior art which can be installedradially about the object to be fastened. Prior to tightening such openclamp structures, the open ends thereof are interconnected by amechanical connection. The tightening of the clamp structure may takeplace by various means, such as, so-called screw-type tighteningdevices, so-called "Oetiker" ears or by a special construction asdisclosed in the aforementioned copending application.

Two principal sources for leakage exist with such types of open clampstructures. On the one hand, leakages may occur because ofdiscontinuities in the form of steps or the like along the innercircumference of the band structure. These problems have been solvedeffectively by a so-called "stepless" clamp structure as disclosed in myprior U.S. Pat. No. 4,315,348. The other possible source of leakage isthe inadequacy of the tightening force with which the clamp structure isclosed. In particular, with the availability of plastic materials havinga relatively high degree of hardness such as "HYTRELL", which are usedin the automotive industry in connection with axle boots, there exists aneed for ever increasing tightening forces. The mechanicalinterconnection disclosed in my prior U.S. Pat. No. 4,299,012 providedan effective solution to the problem of the holding ability of themechanical interconnection by the use of outwardly extendingcold-deformed hooks which take over the force absorption function aftera tab-like, transversely extending guide hook guided the inner and outerband portions toward one another during the tightening of the clampstructure. While the mechanical interconnection disclosed in my priorU.S. Pat. No. 4,299,012 proved quite satisfactory, it neverthelessentailed certain disadvantages. The open clamp structures as disclosedfor example in FIG. 7 of my prior U.S. Pat. No. 4,299,012 are normallystamped out from flat band material and for reasons of economy areshipped as flat blanks from the place of manufacture to the location ofuse thereof, for example, an assembly line in an automotive plant wherethey are preformed into substantially circular shape prior to assemblyover the object to be fastened, as disclosed, for example, in my priorU.S. Pat. No. 4,425,781. Since the hooks are normally formed with theuse of the same die in the automatic machines manufacturing the flatblank, the angle of the guide hook, which thus has a predetermined anglein the flat blank, will vary in the installed condition, depending onthe radius of curvature of the clamping band, i.e., on the diameterthereof. This in turn requires special subsequent attention and remedialaction to maintain optimum conditions for the angle of the guide hook inthe assembled condition of the clamp. Additionally, the guide hook,which is not intended to absorb any significant tightening forces, isformed by a substantially rectangular tab-like member punched out of theband material, thereby leaving an aperture in the band materialcorresponding to the area of the punched-out guide hook. This, in turn,may lead to a tendency of the band material to buckle or kink within thearea where the band material has been reduced by the punched-out guidehook, when the flat blank is bent into the approximately circular shapeof the clamp.

OBJECT OF THE INVENTION

Accordingly, it is a principle of the present invention to provide amechanical interconnection for an open clamp structure which avoids theaforementioned shortcomings and drawbacks encountered with the prior artinterconnections and which will permit the use of even higher tighteningforces for the clamp structure without danger of damage to themechanical interconnection.

The underlying problems are solved according to the present invention inthat the mechanical interconnection includes at least two hooks, one ofwhich is a cold-deformed support hook, while the other is a combinedguide and support hook. In a preferred embodiment of the presentinvention, the combined guide and support hook is formed by a tab-likemember pressed out of the inner band portion and extending in thelongitudinal (circumferential) direction of the band, which is adaptedto engage in a relatively narrow slot-like aperture provided in theouter band portion and also extending in the longitudinal(circumferential) direction of the band. The guide and force engagingsurface of the combined guide and support hook is thereby formed by theinclined edge of the tab-like member facing away from the free end ofthe inner band portion. As a result thereof, the combined guide andsupport hook will initially guide the inner and outer band portionstoward another while at the same time absorbing circumferentiallydirected tightening forces until such time as the cold-deformed hook orhooks become effective by engagement with the respective aperture orapertures thereof, at which time the combined guide and support hookwill continue to perform a force-absorbing function assisting thecold-deformed support hooks to absorb the tightening forces.

The thus constructed tab-like combined guide and support hook is able toabsorb substantial forces in the circumferential direction without thedanger of bending during the tightening of the clamp. Moreover, thelikelihood of kinking or buckling of the band material within the areaof the combined guide and support hook is effectively precluded sincethe combined guide and support hook offers rigidity by its constructionand thus effectively prevents any buckling or kinking. To furtherimprove resistance to buckling and kinking, the combined guide andsupport hook is thereby so arranged that a larger amount of bandmaterial is left on one side thereof than on the other side thatincludes the opening left by the punched out combined guide and supporthook. By thus locating the combined guide and support hook and itscorresponding slot-like aperture substantially centrally in the innerand outer band portions, the holding ability of the mechanicalinterconnection is substantially increased since the combined guide andsupport hook substantially contributes to the holding ability of themechanical interconnection in its installed condition.

These and other objects, features and advantages of the presentinvention will become more apparent from the following description whentaken in connection with the accompanying drawing which shows, forpurposes of illustration only, one embodiment in accordance with thepresent invention, and wherein:

FIG. 1 is a perspective view of an open clamp structure with amechanical interconnection in accordance with the present invention,showing the clamp structure in the preformed, non-assembled condition;

FIG. 2 is a partial side elevational view of the inner band portion ofFIG. 1;

FIG. 3 is a longitudinal cross sectional view through the inner bandportion of FIG. 1;

FIG. 4 is a top plan view of the inner band portion of the clampstructure illustrated in FIG. 1, showing the parts in the flattened-outcondition;

FIG. 5 is a cross sectional view taken along line V--V of FIG. 2; and

FIG. 6 is a cross sectional view taken along line VI--VI of FIG. 2.

Referring now to the drawing wherein like reference numerals are usedthroughout the various views to designate like parts, and moreparticularly to FIG. 1, the open clamp structure generally designated byreference numeral 10 includes inner and outer overlapping band portions11 and 12, respectively, which may be made from one-piece band material13 or may be made of several parts interconnected by appropriateconnections such as mechanical connections, as known to those skilled inthe art. Once assembled over the object to be fastened, the clampstructure may be tightened by any known means, such as, for instance, bycontraction of an ear generally designated by reference numeral 14,which may be a so-called "Oetiker" ear consisting of two leg portionsinterconnected by a bridging portion provided with reinforcing means, orby the structure shown in FIGS. 11 and 12 of my aforementioned patentapplication which obviates the need for an ear.

The clamp structure is preferably of the so-called stepless type ofconstruction and includes a tongue portion 15 at the free end of theinner band portion 11 adapted to engage in a recess formed by apressed-out portion 16 and a step 17, as more fully disclosed in myprior U.S. Pat. No. 4,315,348.

The mechanical interconnection according to the present inventionincludes one or more cold-deformed hooks 20, in the illustratedembodiment, two such cold-deformed hooks 20 which have force-engagingabutment surfaces 21 and are constructed as disclosed in my prior U.S.Pat. No. 4,299,012. As disclosed in this last-mentioned patent, eachcold-deformed support hook 20 is integral with the adjoining parts ofthe band material on all sides thereof, except within the area of thegenerally transversely extending cut which results in the force-engagingabutment surface 21. The support hooks 20 are adapted to engage inrectangular apertures 22, as also disclosed in the last-mentioned priorpatent. According to the present invention, in addition to thecold-deformed support hooks 20, a combined guide and support hook 23 isprovided which is punched and pressed out of the inner band portion 11and extends at substantially right angle to the outer surface thereof(FIG. 6). The outer band portion 12 is provided with a relatively narrowslot 26 for receiving the combined guide and support hook 23. To performthe guide function, the rear edge 25 of the combined guide and supporthook 23, which faces away from the free end of the inner band portion11, is inclined rearwardly outwardly so as to guide the inner and outerband portions 11 and 12 toward one another when the clamp structure istightened about the object to be fastened. The tab-like combined guideand support hook 23 as well as the slot 26 are preferably located withinthe area of the longitudinal center axis 27 of the band (FIG. 4). Thisleaves unequal amounts of band material on the two sides of the combinedguide and support hook 23 due to the fact that the area 28 is reduced bythe existence of the opening 24 compared to the area 29 on the oppositeside of the combined guide and support hook 23. The combined guide andsupport hook is, for example, in the shape of a parallelogram leaving anopening 24 of corresponding configuration. However, it is understoodthat the configuration and shape of the combined guide and support hook23 may also be different from that shown in the drawing to matchparticular requirements, as known to those skilled in the art.

During assembly, the combined guide and support hook 23 is extendedthrough the slot-like aperture 26 whereafter tightening of the clamp iscommenced. As a result of the circumferentially directed tighteningforces, the inclined guide and force-engaging surface 25 causes theinner and outer band portions 11 and 12 to move toward one anotheruntil, during continuing tightening, the cold-deformed support hooks 20become effective to absorb tightening forces by engagement with theirrespective apertures 22. The combined guide and support hook 23, byreason of its particular configuration and construction, thus not onlyperforms a guide function, but also a support function until its supportfunction is assisted by the cold-deformed support hooks 20. However,even after the the cold-deformed support hooks 20 become effective, thecombined guide and support hook 23 will continue to assist in thesupport function since it is able to absorb longitudinally directedforces without bending. Furthermore, the likelihood of buckling orkinking within the areas 28 and 29 is effectively precluded due to theresistance offered by the substantial amount of band material present inthe area 29.

Additionally, the combined guide and support hook 23 offers thepossibility to provide a permanent mechanical connection between theopen ends of the clamp structure by a riveting action, for example, asdisclosed in my U.S. Pat. No. 3,286,314.

While I have shown and described only one embodiment in accordance withthe present invention, it is understood that the same is not limitedthereto but is susceptible of numerous changes and modifications asknown to those skilled in the art and I therefore do not wish to belimited to the details shown and described herein but intend to coverall such changes and modifications as are encompassed by the scope ofthe appended claims.

I claim:
 1. A clamp structure, comprising clamping band means havingopen ends, and means mechanically interconnecting the open ends of theband means including at least two outwardly extending hook means in aninner band portion operable to engage in aperture means in an outer bandportion, at least one of the hook means being a cold-deformed supporthook, characterized in that another one of the hook means is a combinedguide and support hook, said combined guide and support hook havinginclined guide and support surface means operable to initially engagewith the corresponding aperture means in the outer band portion, therear edge of said guide and support surface means sloping upwardly awayfrom the free end of the inner band portion, as viewed in side view ofthe clamp structure so as to guide the inner and outer band portionswith respect to one another while at the same time absorbingcircumferentially directed tightening forces until the cold-deformedsupport hook becomes effective in absorbing tightening forces byengagement of its abutment surface means with the corresponding aperturemeans while the combined guide and support hook will continue to assistin the support function as it is able to absorb longitudinally directedforces without bending.
 2. A clamp structure according to claim 1,wherein said combined guide and support hook is an outwardly directedtab-like member pressed-out of the band material of the inner bandportion and extending generally in the longitudinal direction of theband means.
 3. A clamp structure according to claim 2, wherein saidcombined guide and support hook extends at least approximatelyperpendicularly to the surface of the inner band material with the rearedge thereof which faces away from the free end of the inner bandportion, forming the guide and support surface means.
 4. A clampstructure according to claim 3, wherein said guide and support hook islocated substantially in the longitudinal center of the inner bandportion.
 5. A clamp structure according to claim 3, wherein theremaining band material of the inner band portion which is left on oneside of the guide and support hook, as viewed in the transversedirection of the inner band portion, is wider than on the other side ofthe guide and support hook to thereby increase resistance to buckling.6. A clamp structure according to claim 5, wherein the remaining bandmaterial of the inner band portion is reduced on the other side by thearea of band material representing the area of the pressed-out guide andsupport hook.
 7. A clamp structure according to claim 6, wherein saidarea is generally in the form of a parallelogram.
 8. A clamp structureaccording to claim 7, wherein the aperture means in the outer bandportion of each cold-deformed support hook is of generally rectangularconfiguration while the aperture means for the combined guide andsupport hook is a relatively narrow slot extending generally in thelongitudinal direction of the band means.
 9. A clamp structure accordingto claim 8, wherein said slot is located substantially in thelongitudinal center of the outer band portion.
 10. A clamp structureaccording to claim 1, wherein the remaining band material of the innerband portion which is left on one side of the guide and support hook, asviewed in the transverse direction of the inner band portion, is widerthan on the other side of the guide and support hook to thereby increaseresistance to buckling.
 11. A clamp structure according to claim 10,wherein the remaining band material of the inner band portion is reducedon the other side by the area of band material representing the area ofthe pressed-out guide and support hook.
 12. A clamp structure accordingto claim 11, wherein said area is generally in the form of aparallelogram.
 13. A clamp structure according to claim 1, wherein theaperture means in the outer band portion for each cold-deformed supporthook is of generally rectangular configuration while the aperture meansfor the combined guide and support hook is a relatively narrow slotextending generally in the longitudinal direction of the band means. 14.A clamp structure according to claim 13, wherein said slot is locatedsubstantially in the longitudinal center of the outer band portion.